An apparatus and a method for transmitting feedback information of an asymmetric frequency band in a wireless communication system supporting multiple bands are provided. The feedback information transmission method includes, when at least two frequency bands used by a mobile station includes at least one asymmetric frequency band, confirming feedback channel information for the asymmetric frequency band based on system channel information of the asymmetric frequency band, and transmitting feedback information for the asymmetric frequency band over the confirmed feedback channel. The feedback channel information includes feedback channel information for the asymmetric frequency band allocated to a symmetric frequency band.